If the marginal revenue is 28 and elasticity of demand is 3 then the price is:

Answer

To solve the problem, we need to find the price (P) given the marginal revenue (MR) and the elasticity of demand (E). Here are the steps to find the solution:

### Step 1: Write down the given values
- Marginal Revenue (MR) = 28
- Elasticity of Demand (E) = 3

### Step 2: Use the formula for Marginal Revenue
The formula for marginal revenue in terms of price and elasticity of demand is given by:
\[ MR = P \left(1 - \frac{1}{E}\right) \]

### Step 3: Substitute the known values into the formula
Substituting the values of MR and E into the formula:
\[ 28 = P \left(1 - \frac{1}{3}\right) \]

### Step 4: Simplify the expression inside the parentheses
Calculate \(1 - \frac{1}{3}\):
\[ 1 - \frac{1}{3} = \frac{3}{3} - \frac{1}{3} = \frac{2}{3} \]

### Step 5: Substitute back into the equation
Now substitute this back into the equation:
\[ 28 = P \left(\frac{2}{3}\right) \]

### Step 6: Solve for P
To isolate P, multiply both sides by \(\frac{3}{2}\):
\[ P = 28 \times \frac{3}{2} \]

### Step 7: Calculate the value of P
Calculating the right side:
\[ P = 28 \times \frac{3}{2} = \frac{84}{2} = 42 \]

### Final Answer
Thus, the price (P) is:
\[ P = 42 \]

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